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A Honeywell Company

Gas Burner Safety Control

INTRODUCTION

The burner control box DKG 972 controls and supervisesatmospheric burners for gas. They are approved and certifiedaccording to the applicable European standards andregulations.The microprocessor-based programming sequence ensu-res extremely stable timings independent of voltage varia-tions, ambient temperature and/or switch-on cycles. Thebuilt-in information system not only provides a continuousmonitoring of the actual state of the box (very helpful es-pecially for monitoring the start-up phase) but also informsabout the cause of a possible lock out. The lock out causeis stored in such a way that it can be retrieved even after apower failure.The control box is designed for maximum safety in case offluctuations in the voltage supply. If the mains voltage dropsbelow the permitted level, operation is interrupted and thecontrol box automatically prevents the start sequence frombeing repeated. In this way, the safety of the system is notput at risk by a drop in the mains voltage. This low-voltageprotection works not only during start-up but also perma-nently during operation.

CONSTRUCTIONAL FEATURES

The control box circuitry is protected by a flame resistant,transparent plug-in type plastic housing. A central fixingscrew locks the control box to the wiring base.The plug-in control box incorporates the microprocessorbased timer, flame check and reset circuits.Manual reset from lock out and set to lock out is provided bya push button with an integrated LED information system.A variety of cable entry points provides complete flexibilityfor electrical wiring.The wiring base S98 is equipped with spare- and extraterminalsand allows together with a variety of cable entry points utmostflexibility of electrical wiring.

The DKG 972 are compatible with the TFI 812.Different are only the pre- and post-ignition times.

Max. heating power according the limits in the Gas ApplianceDirective.

DKG 972

TECHNICAL DATA

Operating voltage 220 / 240 V (-15... +10%)50 Hz (±5%)

or 110 / 120 V (-15... +10%)60 Hz (±5%)

Fuse rating 10 A fast, 6 A slowPower consumption ca. 12 VAMax. load per output- term. 3 ignition trafo 1.0 A, cos ϕ 0.2- term. 5 + 6 solenoid valves 0.5 A, cos ϕ 0.4- term. 7 alarm indicator 0.5 A, cos ϕ 0.4- term. 4 auxiliary blower 2.0 A, cos ϕ 0.4total load 4.0 A, cos ϕ 0.4

max. 16 A during 0,5 secReset time from lock out none

Re-cycling / repetition (max. 4x) after a loss-of-flame duringoperation

Sensitivity 1 µAmin. ionisation current required 1.5 µASensitivity for stray light 0.4 µAIonisation probe insulation probe - earth

greater than 50 MΩStray capacitance probe- earth

less then 1000 pFmax. cable length < 3 mFlame detectors

IRD 1020.1 side-on or end-on viewingUVD 971 end-on viewing

Weight incl. Wiring base 190 gMounting position anyProtection class IP 40Approved ambient parameterfor control and flame detector max. 95% at 30° C- for operation -20° C... +60° C- for storage -20° C... +80° CBuild-up of ice, penetration ofwater and condensing water are inadmissibleApprovals accordingto European standards EN 298 and EN 230, as

well as all other relevantDirectives and standards

Classified acc. to EN 298 ATLLXN

For 2-stage atmospheric gas burners

Flame detection:- Ionisation probe- Infrared-flicker detector IRD 1020.1- UV flame sensor UVD 971

Model waiting time start pre-ignition time Stray light monitoring safety time post-ignition time delay 2nd-stagetw tvz tf ts tn tv2

05 12 3 5 5 4 2510 12 3 5 10 9 25

Table of timings (sec.)

EN

1C-0

127S

Z20

R03

05

2

1.2 Lock-out diagnoses

In case of a failure the LED is permanently illuminated. Every10 seconds the illumination is interrupted by a flash code,which indicates the cause of the error. Therefore the followingsequence is performed which is repeated as long as the unitis not reset.

Sequence:

illuminated phase dark phase Flash-Code dark phase

for 10 sec for 0.6 sec for 1.2 sec

Error diagnosisError message Flash-Code Possible faultlockout within lock out safety time

no flame establishmentstray light stray light

during monitored phase,detector may be faulty

Flash-Code for manual lock outmanual/external lock out(see also 3. lock out and reset)

2. Flame detection

The following types of flame detectors are suitable:

– Ionisation probe, temperature resistant material, wellinsulated (material and insulation same as for ignitionelectrode).

– Infrared-flicker detector type IRD 1020.1 with mountingflange M 93 or the UV solid state flame sensor UVD 971.

Flame detection using an ionisation probe is only possiblein conjunction with mains supplies which provides a neu-tral earth connection.Connecting the IRD 1020.1 or UVD 971 the correct wiringhas to be observed.

2.1 Stray light monitoring

The stray light check is performed at the end of the pre-purge time for thr duration as mentioned in the table oftimings.

APPLICATION FEATURES

1. Information system

The information system is microprocessor based and re-ports on all aspects of burner control box operation andflame supervision. It informs continuously about the actualprogramming sequence the unit is just performing. Besidesmonitoring of the programming sequence it also allows toidentify errors during start-up of operation without anyadditional testing devices. The automatically performeddiagnosis is a valuable tool which facilitates service/maintenance work and therefore saves costs. The analysesof the error cause can be done directly on stage or if notpossible afterwards as the lock out reason is stored in a non-volatile lock out mode memory.The information system communicates with the outsideworld using a LED (the used Flash-Code is similar to theMorse-Code). The messages are optically transmitted by aappropriately flashing LED. Using an additional terminal(optional), the messages can be recorded and displayed ineasy readable form.

1.1 Programming sequence display

The built-in microprocessor controls not only the pro-gramming sequence but the information system too. Theindividual phases of the programming sequence aredisplayed as Flash-Code.The following messages can be distinguished:

Message Flash-Codewaiting time .twpre-ignition .tvzsafety time ts .post ignition tndelay time to valve V2 .tv2running _

low mains voltage _Internal fuse defect _> control box defect

Description = short pulse = long pulse. = short pause_ = long pause

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3. Lock out and reset

The unit can be reset or brought into lock out mode in twodifferent ways:

InternalIn the lock out case the unit can be reset by pushing the built-in button meaning a new start-up cycle is performed.

ExternalInstead of using the built-in lock out button the samefunction can be achieved by using an external button whichconnects terminal 9 with A (see also circuit and blockdiagram).

If the pushputton (internal or external) is pressed duringnormal operation or during the start sequence for more then3 sec. and afterwards released, the control box will performa shutdown.

Please noteThe unit can only be brought to lockout mode orbe reseted if power is applied to the unit.

4. Low-voltage protectionat 220 / 240V (110 / 120V) nominal voltage

The mains voltage has to be more than 187 Veff (94 Veff ) inorder to allow the unit to perform a start-up.The mains voltage is not only monitored in the start-upphase but also permanently during operation. If the voltagedrops below < 160 Veff (80 Veff ) during start-up or run timethe control box proceed to safety shut-down and goes intoa waiting status. If the voltage rises again, the control boxperforms automatically a start-up as soon as the mainsvoltage is > 187 Veff (94 Veff ) .

5. Safety

The design and control sequence of the DKG 972 controlswill comply with the currently applicable standards andregulations (see also TECHNICAL DATA).

6. Mounting and electrical wiring

Wiring base:– 3 earth terminals with additional terminal for burner

earthing– 3 neutral terminals with internal permanent connection to

neutral terminal 8– 2 independant spare terminals (S1 and S2)– extra terminals A, B and C are standard (wiring base S98

12-pin)– 2 slide-in plates and 2 easy knock out holes plus 2 knock

out holes in the base bottom faciliate the base wiring

Please noteTo assist trouble-free operation the main neutralconnection terminal 8 in the wiring base must befully tightened. The terminal screws are already inthe undone position. To connect a wire to theterminal, the screw only needs to be fastened.

General: The control box and detector probes should not besubjected to excessive vibration.

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INSTALLATION INSTRUCTIONS AND MAINTENANCE

1. Important notes

– The controls must be installed by qualified personnelonly. The relevant national regulations have to beobserved.

– On commissioning the wiring has to be carefully check-ed according the appropriate diagram, Incorrect wiringcan damage the unit and endanger the installation.

– The fuse rating has to ensure that the limits specified inTECHNICAL DATA will not be exceeded. If these precau-tions are not observed, the effect of a short circuit cancause severe damage to the control and installation.

– For safety reasons a minimum of one control shutdownevery 24 hours has to be observed.

– Disconnect the mains before the control box is pluggedin or out.

– The control box is a safety device and must not beopened!

2. Function control

For safety reasons the flame detection system should betested on commissioning the installation as well as after aservice or longer shut-down.

a) Attempt to start with gas valve closed:– At the end of the safety interval

-> Lockout

b) After a normal start, with the burner in operation, closethe gas valve:– After restart at the end of the safety interval

-> Lockout

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3. Fault finding

The built-in information system facilitate the trouble shootingin the case of problems occurring during start-up or duringoperation.A list of possible lock out messages can be found inAPPLICATION FEATURES chapter 1.2.

Please note:The control box is locked in lock out modeand the reasen for the lock out is displayeduntil the control box is reset, either by aninternal or external reset (see also subject “3.Lock out and reset").

Removing the control box from its wiring base or byinterrupting the supply line may not reset a lock out. Therefore,by applying power, it needs 2-3 secs. before the control boxgoes to lock out again and the cause of the last lock out.

Error Possible faultBurner not working - Thermostat circuit open

- Faulty electrical wiring- Mains voltage < 187 V (< 80 V)- Terminal A continuously on power (e.g. terminal A is used as a support terminal)

After 2-3 secs. after applying - Control box has not been resetedpower. the unit goes tolock outBurner starts, - stray light signal during waitingflame not established, timelock out - no ignition or no fuelBurner starts, -no or too low flame signal (min.flame established, valves see TECHNICAL DATA)after safety time, -wrongly wired, phase and neutrallock out reversed

- Ionisation probe dirty, broken orhas contact to frame ground

- too little light on flame sensIor(IRD)

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BLOCK DIAGRAM DKG 972

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term. 8

term. 1

term. 9

blue

black

brown

IRD 1020.1UVD 971

IRD- OR UVD CONNECTION

max. 10 A fast6 A slow

Ph

IS

N

1 2 3 4 5 6 7 8 9 A

HS ST RT EV

Z

V1

SA

Flameamplifier

Reset µC

Reset andlock out

Powersupply

monitoring

1 3 4 5 6 7 8 9 A

rz rv1

rv2

rs

RZ RV1 RV2 RS

Fault displayInformation

systemEEPROMOscillator

tw tf tvz tn ts tv2

HS Mains switchGW Gas proving switchST Limit thermostatRT Control thermostatEV External reset and lock out buttonIS Ionisation probe

(IRD 1020.1, UVD 971see separate diagram)Z IgnitionV1 Solenoid valve, 1st-stageV2 Solenoid valve, 2nd-stageSA External lock out signalM Auxiliary blower

tw Waiting timetf Stray light monitoringtvz Pre-ignition timetn Post-ignitionts Safety timetv2 2nd-stage delay

µCWatchdog

Mainsmonitoring

Powersupply

GW

V2

M

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A Honeywell Company Satronic AGHoneywell-Platz 1Postfach 324CH-8157 Dielsdorf

DKG 972 AND SOCKET

62,5

4,5

38,5

24

86 60

24

3030

44

M4

Earth

Reset button

57-60

2535

30Underside cableentry ø16 mm

16

DKG 972

ORDERING INFORMATION

ITEM DESIGNATION ITEM NO.Control box DKG 972 Mod. 5 0332005Control box DKG 972 Mod. 10 0332010Control box DKG 972 Mod. 10 110 / 120V 50Hz 0332310Control box DKG 972 Mod. 10 110 / 120V 60Hz 0332410Socket Wiring base S98 12-pin 75310Insert plate PG-Plate 70502optional Cable entry plate 70503Flame detector IRD 1020.1 end-on 16532Flame detector IRD 1020.1 left 16533Flame detector IRD 1020.1 right 16531optional UVD 971 16722Support for IRD Holder M93 for IRD 1020 59093Support for UVD Holder M74 for UVD 59074Connection cable Plug type, 3 core cable, 0.6 m with tag wire ends 7236001

The above ordering information refers to the standard version.Special versions are also included in our product range. Specifications subject to change without notice

Slide-in plate

VARIATION IRD

right

left

axial

UVD 971 IRD 1020.1

29 50UVD = 29IRD = 44

21,8

ø13,

5

UVD = 89IRD = 104

29

21,8

HOLDER M 93 FOR IRD35

3

14

4.5

26

15.1

48

17

ø20.5

4

HOLDER M 74 FOR UVD

ø 14

353

ø20

4,5

26

448 7